diff --git a/boost-1.83-fix-no-member-named_that_error.patch b/boost-1.83-fix-no-member-named_that_error.patch
new file mode 100644
index 0000000..e3efd01
--- /dev/null
+++ b/boost-1.83-fix-no-member-named_that_error.patch
@@ -0,0 +1,24 @@
+From 49ccf9c30a0ca556873dbf64b12b0d741d1b3e66 Mon Sep 17 00:00:00 2001
+From: Arvid Norlander <arvid-norlander@users.noreply.github.com>
+Date: Fri, 8 Nov 2024 16:48:43 +0100
+Subject: [PATCH] Fix build on clang-19 (which checks more things in
+ uninstantiated templates)
+
+Fixes issue #402
+---
+ include/boost/thread/future.hpp | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/include/boost/thread/future.hpp b/include/boost/thread/future.hpp
+index 00f504b9b..d15d7ffa5 100644
+--- a/boost/thread/future.hpp
++++ b/boost/thread/future.hpp
+@@ -4668,7 +4668,7 @@ namespace detail
+       }
+       run_it& operator=(BOOST_THREAD_RV_REF(run_it) x) BOOST_NOEXCEPT {
+         if (this != &x) {
+-          that_=x.that;
++          that_=x.that_;
+           x.that_.reset();
+         }
+         return *this;
diff --git a/boost.spec b/boost.spec
index 1bc1719..31a0a76 100644
--- a/boost.spec
+++ b/boost.spec
@@ -46,7 +46,7 @@ Name: boost
 %global real_name boost
 Summary: The free peer-reviewed portable C++ source libraries
 Version: 1.83.0
-Release: 5%{?dist}
+Release: 6%{?dist}
 License: BSL-1.0 AND MIT AND Python-2.0.1
 
 # Replace each . with _ in %%{version}
@@ -162,6 +162,9 @@ Patch7: boost-1.81.0-random-test-fixes.patch
 
 Patch8: boost-1.83-regex-test-fixes.patch
 
+# https://github.com/boostorg/thread/pull/408
+Patch9: boost-1.83-fix-no-member-named_that_error.patch
+
 %bcond_with tests
 %bcond_with docs_generated
 
@@ -1291,6 +1294,10 @@ fi
 %{_mandir}/man1/b2.1*
 
 %changelog
+* Wed Oct 01 2025 Federico Pellegrin <fede@evolware.org> - 1.83.0-6
+- Backport patch to fix build of boost thread on Clang19 and later
+  Resolves: RHEL-118607
+
 * Tue Oct 29 2024 Troy Dawson <tdawson@redhat.com> - 1.83.0-5
 - Bump release for October 2024 mass rebuild:
   Resolves: RHEL-64018